In modern semiconductor devices, the ever increasing device density and decreasing device dimensions demand more stringent requirements in the packaging or interconnecting techniques of such devices. Conventionally, a flip-chip attachment method has been used in the packaging of IC chips. In the flip-chip attachment method, instead of attaching an IC die to a lead frame in a package, an array of solder balls is formed on the surface of the die.
Controlled Collapse Chip Connection New Process (“C4NP”) is another method of depositing conducting bonding material onto molds. C4NP is a subset technology of IMS, which is further discussed in U.S. Pat. No. 5,244,143 and is commonly owned by International Business Machines Corporation, and is hereby incorporated by reference in its entirety. C4NP allows the creation of pre-patterned solder balls to be completed while a silicon wafer is still in the front-end of a manufacturing facility, potentially reducing cycle time significantly. The solder bumps can be inspected in advance and deposited onto the silicon wafer in one simple step. In this technology, a solder head with an injection aperture comprising molten solder scans over the surface of the mold. In order to fill the cavities on the mold, pressure is applied onto the reservoir of the C4NP head which comprises the molten solder as it is scanned over the cavities. The filling of the C4NP mold plate in a reliable, high speed and cost-effective manner is a challenge. Current C4NP systems use a scanning fill head which covers only a portion of the total area to be filled at any one time. This approach requires sealing elements, which must contain solder, air, and/or vacuum at significant pressure differentials while the seal is scanned across the mold plate.
Therefore a need exists to overcome the problems with the prior art as discussed above.